DARCA, I'm under the impression you're not quite asking for a straight up GalCiv 3 release on the app store, but a standalone GalCiv-like game that's more approachable basically. While that's not a bad idea in terms of the mobile market, that would take a lot of work and potentially a modified or seperate framework that has less features. That would eat up a lot of development resources that could go towards actually completing the game we want. It would also likely need to be 32-bit, as I'm not sure if an iPad and such could do complex enough processing involved with 64-bit unless some other aspect was sunk down to compensate.
There's also been some solid strategy games on the mobile market that just didn't succeed. While on-the-go GalCiv would be fun for a niche market, in reality the people who would really enjoy it are the ones who would already enjoy the full game. Mobile gamers like things they can pick up and play for 5 minutes, then set down and do something else. Or multitask while playing easily. As some irony though, the mobile market thrives on quick games and more complicated ones struggle, but people will still spend hours on those fast games anyways. I'll never understand that.
Not to stray too far off topic, but this is why Nintendo handhelds continue to thrive even against mobile competition: they offer games that are usually easy to pick up and play, but are much more in-depth and can be appreciated in both small bites and lengthy sessions. Basically it's a middle ground market they've found in handheld gaming.
I would also like to note: the target market of GalCiv 3 is 4x PC gamers, which can be male, female, kid or adult. Age or gender doesn't equate to ability to play a game. Everyone has their own preferences. I've been playing strategy PC games since around age 7 or so, because the challenge was engaging and my older brother assured me that losing was an important part of learning a game haha. Anyone can learn, it's just a matter of having the interest in the game genre enough to do so.